Abstract: To permit a threading roller chain for a printing machine to flex outside of a plane, for example parallel to the printing machine, and permit passage of the threading mechanism about turning bars and the like, the roller chain is formed of a plurality of bolt elements (1, 16) retaining rollers (2, 19) thereon, and rotatable within the guide track (15, 29). The bolt elements (1, 16) are connected by flexible, preferably steel cables or ropes (4, 5, 22), passed through holes (11, 23) in the bolts and retained therein by pinch or clamp deformation of the bolts. The cables or ropes accept tension forces between adjacent bolts and rollers. To accept compression forces, essentially non-compressible spacer elements (6, 24) are placed between adjacent bolts, preferably in form of tightly wound spiral springs, surrounding the respective cables or ropes. The cables or ropes, with the spacers thereabout, can be passed alongside a single roller (FIGS.

Abstract: To provide for controlled braking effort on a selected paper roll (5) from which a web (14) is applied to a utilization machine, and additionally for fast-stop or holding conditions, the roll is coupled to an operating disk brake (10) which receives braking pressure from a regulated pressure source. Additionally, rapid-stop brake calipers forming a rapid-stop brake (11) are applied to the disk, preferably having a higher braking friction coefficient, and controlled from the regulated pressure via a fluid disjunctive or OR-gate valve (42). A magnetic valve (36), controlled by a computer-controller (28), selectively switches the controlled fluid pressure through the OR-gate valve (42) only to the operating brake or to the fast-stop brake and, via a branch connection (46a), also to the operating brake.